1. Field of the Disclosure
The present disclosure relates to a light emitting device having a monolithic protection element, and more particularly, to a light emitting device having a protection element protecting the light emitting device from static electricity.
2. Description of the Related Art
Light emitting devices such as LDs, LEDs, or the like are highly efficient light sources and are utilized in various fields. However, such a light emitting devices are very brittle with respect to an electric impact such as static electricity. The static electricity discharged in a reverse bias state can damage the internal physical structure of the light emitting device.
An additional protection element is used to protect the light emitting device from such an electrostatic discharge (ESD). The protection element is generally a zener diode connected to the light emitting device in parallel in a reverse polarity. Thus, an electrostatic current applied to the light emitting device in a reverse direction is bypassed through the protection element.
Initially protection elements were manufactured as separate chips and then mounted on a lead frame along with the light emitting devices. The protection elements manufactured as separate chips require wire bonding for an electric connection and thus increase the manufacturing cost.
In a case of a light emitting device using the generally employed flip chip bonding method, a protection element is formed on a substrate to which the light emitting device is bonded. Thus, the light emitting device and the protection element are connected to a conductive bump used for bonding. In this conventional method, the protection element must be formed on the substrate to which the light emitting device is bonded, using a semiconductor thin film process. Thus, manufacturing cost is inevitably increased.
U.S. Patent No. 6,593,597 discloses a structure into which a light emitting device and a protection element are monolithically integrated on a transparent substrate. Since the light emitting device and the protection element are monolithically integrated on the substrate, this structure has significantly more advantages than the previously-described light emitting device. however, the protection element must use a portion of an effective area of the light emitting device. As a result, the area of the light emitting device occupied within a limited area is reduced.